The invention provides a sound producing device capable of producing sound by using air. The sound producing device comprises an air cylinder, a piston and a gun head. The piston is sleeved with a planar sealing ring which can prevent air circulation of an upper air chamber and a lower air chamber of the air cylinder. The cylinder wall portion, above a protruding table, of the air cylinder is uniformly provided with explosion openings. When the piston is attached to the protruding table, the sealing ring on the piston is right pressed against the inner sides of the explosion openings to seal the explosion openings. The device is wide in application range and can be applied to flammable places such as coal mines and oil and gas fields; the device can even be used in water; the device has economic value, social value and cultural value; selling air firecrackers can bring economic income for employees, enterprises and the government, so that the economic value is obvious; the sound producing device is a safe and environmentally-friendly firecracker, and pollution can be reduced greatly if the device replaces an explosive firecracker, so that the sound producing device is of great social importance; the sound producing device enables people to continue and develop the traditional firecracker setting-off culture without polluting the environment.